Navigon Triansonic PNA 4000 Replacement Battery 3.7V 1700mAh

Navigon Triansonic PNA 4000 — 3.7V Li-ion Replacement Battery (541380530006)

This 3.7V Li-ion cell at 1700mAh replaces the original battery in the Navigon Triansonic PNA 4000 portable GPS navigator. It restores power to the unit when the factory cell can no longer hold a charge. Voltage and connector match the original spec.

• Triansonic PNA 4000 compatibility: The PNA 4000 uses a fixed 3.7V single-cell architecture with a specific connector and BMS handshake. This cell matches that voltage rail and connector pinout, so the device powers on and communicates with the battery management circuit correctly.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the PNA 4000 platform and confirmed the BMS accepted the cell without fault codes. Charge termination triggered cleanly at 4.2V as expected for standard Li-ion chemistry.
• Cold-start satellite acquisition after swap: After fitting this cell and powering on for the first time, take the unit outdoors and let it run. The GPS performs a full cold start after any power interruption — first satellite lock can take 5–10 minutes outdoors. Subsequent warm starts drop to under a minute once almanac data is cached.

GPS accuracy reduced at low battery on the PNA 4000

When the PNA 4000 battery voltage drops toward the lower threshold, the device can reduce power to the GPS receiver module to extend remaining operation. This causes position drift or wider accuracy circles on the map display. It is not a hardware fault — it is a power-management behaviour tied to receiver sensitivity. Keeping the battery above 3.6V during active navigation prevents the unit from entering this reduced-sensitivity state.

PNA 4000 shuts off without warning before the battery indicator reaches empty

This happens because the battery percentage indicator relies on a voltage-to-capacity curve calibrated to the original cell. A new cell — or a degraded one — can sit at a different actual voltage than the indicator expects, so the low-battery warning fires late or not at all. The device hits the hardware cutoff threshold before the visual warning appears. Run one full charge-to-discharge cycle after fitting the new cell to let the firmware recalibrate the curve against the actual resting voltage at each state of charge.